Veterian
A Medical researcher.
Obviously there is no such person researching cures. Cures are mostly ignored.
A person qualified to treat diseased or injured animals is an VET-ER-I-NAR-I-ANVETERINARIAN
A person that assists in handling animals can be called a groom if they work with horses. A person who works with zoo animals might be called a trainer, zookeeper, or handler. A person who raises animals for food might be called a rancher or dairy farmer.
A person that studies animals is called a Zoologist.
Animals help by making people happy. And some derived animals are used for medicines and cures.
zookeeper
zookeeper
A Veteranarian
Pharmacologist
They are called a Menagerie Man.
A lover of animals or a person opposed to animal cruelty is called a zoophile.